Piano-action.



PATENTED OCT. 25, 1904.

W. KRETER.

PIANO ACTION.

APPLIPATION mum T23. 26. 1902.

N0 MODEL.

*" INVENTOR WITNESSES Patented October 25, 1904.

PATENT OFFICE.

WILLIAM KRETER, OF NEW YORK, N. Y.

PIANO-ACTION.

SPECIFICATION forming part of Letters Patent No. 773,019, dated October25, 1904.

'Application filed February 26, 1902. Serial No. 95,781. (No model.)

To all whom it may concern.-

Be it known that 1, WILLIAM KRETER, a citizen of the United States,residing in the borough of Manhattan, of the city of New York, in thecounty and State of New York, have invented a certain new and usefulImprovement in Piano-Actions, of which the following is a specification.

It is well known that in adjusting pianoactions the risers orlifting-rods (or the connection between them and the keys) are ad.-justed so that the jacks will be in close proximity to the hammer-buttsto avoid lost motion at the butts when the keys are operated. When thehammer-rail is moved forward by the soft pedal for pianissimo effects,the hammers are carried toward the strings, and this movement removesthe hammer-butts from engagement with the jacks, thereby causingconsiderable lost motion when the keys are operated. V

The object of my invention is to overcome this lost motion and at thesame time preserve the regulation of the piano-action.

With this object in view I havedevised means for compensating for theforward movement of the hammers through the operation of the soft pedal,so that there will be no lost motion between the keys and hammerbutts,and which compensating means preferably operates simultaneously with theoperation of the soft pedal; I further provide means for adjusting saidcompensating means after the action is regulated by means of the usualadjusting devices employed for that purposethat is to say, the improvedaction comprehends the usual elements, including the adjusting devicesfor regulating the action, the compensating mechanism for preventing thelost motion, and the adjusting devices for adjusting said mechanismindependently for eachkeyand independently of the regulatingadjustments, so that the adjustments of the compensating mechanism willnot affect the regulation obtained by the firstnamed adjusting devices.

In the preferred form of my invention as applied to a well-known type ofupright action the compensating mechanism consists of a series ofpivoted levers, (hereinafter referred to as the compensating levers,)one on each lifting-rod, a horizontally-pivoted bar (hereinafterreferred to as the compensator-bar) extending over the inner ends of thekeys and which is raised through the agency of the soft pedal to bringit into engagment with and raise the compensating levers simultaneouslywith the forward movement of the hammers by the soft pedal, so that thelifting-rods and jacks will be raised and prevent lost motion betweenthe jacks and hammer-butts, and means for independently adjusting theoperation of each compensating lever relative to its jack andindependentlyof the means for regulating the action. The compensatinglevers are preferably pivoted in a straight line near the foot of eachlifting-rod, and as the adjusting means for these levers I preferablyprovide a fulcrum for each lever, which is an adjustable post on eachkey, so that each compensating lever may be adjusted independently ofthe others relative to its own jack and compensator-bar andindependently of the adjusting devices employed for regulating theaction, so that notwithstanding any adjustments of the compensatingdevices that may be necessary the original regulation of the action willbe preserved.

My invention is illustrated in the accompanying drawing, whichillustrates a single key and its hammer-action with my improvementapplied thereto, the solid lines representing the action when thehammer-rail is in its normal position,and the dotted lines indicatingthe relative positions of the parts following the simultaneous movementsof the hammerrail and compensator-bar through the operation of the softpedal.

Referring to the drawing, A indicates the usu'al key Working on apivot-pin (rand provided with a screw-post (1/, upon which rests alifting-rod B. This rod is hinged to the usual jack-lever carrying thespoon for 013- erating the damper and the back catch for the hammer. Thelifting-rodB is also hinged to a link 6, which is hinged on a cross-barZ) and serves to hold the lifting-rod in line with the screw-post a onthe key.

0 is a jack of ordinary construction de- 100 signed to strike the butt(Z of the hammer D, and c is the usual adjusting-button for tripping thejack after actuating its hammer. In the action illustrated in thedrawing the hammer-rail consists of a movable section E and a stationarysection E, the movable section being carried by pivoted arms which areconnected with the soft pedal bya rod and lever, as usual.

It will be understood that in adjusting the action shown in the drawingthe adjustingscrew (1, is set so that the end of the jack (7 will touchthe butt (Z without raising the hammer-arm from the hammer-rail. It willbe observed that when the hammer-rail E is moved forward, as shown indotted lines, there is a considerable clearance between the end of thejack and the butt. This cl arance is taken up by raising the lifting-rodB, jacklever, and jack by means of the short lever F, pivoted near thefoot of the lifting-rod B. by raising the compensator-bar G through thesoft pedal. It will be understood that the connection between the bar Gand the soft pedal is such that the vertical movement of the bar will bejust sufficient to raise the jacks the desired distance. This bar G iscarried by suitable arms 9, pivoted at suitable points on the frameworkof the piano. The means for adjusting lever F to produce the proper liftof the jack to compensate for the forward movement of the hammer by thehammerrail is an adjustable post H, having a screw working in the key A.To obtain this adjustment for each key the soft pedal is depressed,which places the various parts in the dotted-line positions, and if ajack does not properly engage its hammer-butt its respective lever F isadjusted to raise or lower the jack by readjusting the post H.

It will be observed that the adjustments of posts H do not alter theoriginal adjustments of the hammer-butts, jacks, and rods B inregulating the action, since the adjustments between said rods and theirregulating-screws a" are not altered by the adjustments of posts H, andhence the regulation of the action is preserved.

It will be noticed that when the parts are in the dotted-line positionand the key A is depressed rod G becomes the fulcrum of lever F and postH raises its end of the lever and serves as the means for imparting themovement of the key to rod B and jack (1 until screw (t engages the footof rod B, whereupon the upward movement of rod 13 is continued by thedirect engagement of the foot of said rod with screw-rod a.

From the foregoing it will be seen that post H constitutes the fulcrumfor lever F when the soft pedal is depressed to restore the jack to itsproper position relative to the hammer-butt and that while in thisposition rod (1 becomes the fulcrum for lever F when the key isdepressed.

Frame 1 am aware that in some piano-actions the keys are so balanced bysprings or weights that when the hammers are moved forward by thehammer-rail the jacks will be caused to follow the butts and maintainengagement therewith. I am also aware that in another form of action theconnection between the jack-levers and keys is such that upon theforward movement of the hammers by the hammer-rail the jack-levers willbe raised correspondingly by the straps and pins connecting the buttsWith the jack-levers, and consequently the jacks will follow thehammerbutts; but this means is not very accurate, and, besides, the keyswill drop a corresponding distance, which will affect the touch of theoperator. 1 am also aware that in a still other form of action means hasbeen provided for raising the jacks simultaneously with the forwardmovement of the hammers by the hammer-rail and which means wascontrolled by a bar actuated from the soft pedal. In each of thesearrangements, however, no means was provided for accurately adjustingthe compensating devices for each key independently of each other andwithout disturbing the regulation of the action to compensate for theforward movement of the hammers by the hammer-rail, and in the lastnamedarrangement the bar for controlling the compensating means actedsimilarly for each key, and no means was provided for correcting faultyconstruction, and even if the parts were entirely accurate whenoriginally put in position no means was provided for readjustment tocompensate for wear and warping of the wooden parts.

\Vhat I claim is 1. In a pianoaction, the combination with a hammer andits jack, the adjusting means therefor, and the hammer-rail, of meansfor compensating for the forward movement of the hammer by thehammer-rail to maintain the relative adjustments of the hammer and itsjack, and a device for adjusting said compensating means to preserve theregulation effected by the first-named adjusting means.

2. In a piano-action, the combination with a hammer and its jack, theadjusting means therefor, and the hammer-rail, of means operatedsimultaneously with the hammer-rail for compensating for the forwardmovement of the hanimer by the hammer-rail to maintain the relativeadjustments of the hammer and its jack, and a device for adjusting saidcompensating means to preserve the regulation effected by the firstnamed adjusting means.

3. In a piano-action, the combination with a hammer and its jack, theadjusting means therefor, the key and the operating connection betweenthe same and the jack-lever, and the hammer-rail, of means cooperatingwith the key and said operating connection to compensate for the forwardmovement of the hammer by the hammer-rail to maintain the relativeadjustments of the hammer and its jack, and a device for adjusting saidcompensating means to preserve the regulation effected by the firstnamedadjusting means.

L. In a piano-action, the combination with a set of hammers, their jacksand jack-levers, the separate adjusting means therefor, and thehammer-rail, of a compensator-bar, a compensating lever for each jackarranged to be engaged by said bar to shift the jacks when I the hammersare moved forward by the hammer-rail, an operating connection betweensaid compensator-bar and the pedal for operating the hammer-rail, andmeans for adjusting said compensating levers independently of each otherrelative to their jacks and said compensator-bar to preserve theregulation effected by the first-named adjusting means.

5. In a piano-action, the combination with a set of hammers, their jacksand jack-levers, the separate adjusting means therefor, and thehammer-rail, of a compensator-bar, a compensating lever pivoted on thelifting-rod of each jack-lever, and arranged to be engaged by said barto shift the jacks when the hammers are moved forward by thehammer-rail, an operating connection between said compensator-bar andthe pedal for operating the hammer-rail, and means for adjusting saidcompensating levers independently of each other relative to their jacksand said compensator-bar to preserve the regulation effected by thefirst-named adjusting means.

6. In a piano-action, the combination with a set of hammers, their jacksand jack-levers, the separate adjusting means therefor, and thehammer-rail, of a compensator-bar, a compensating lever for each jack,and arranged to be engaged by said bar to shift the jacks when thehammers are moved forward by the hammer rail, an operating connectionbetween said compensator-bar and the pedal for operating thehammer-rail, and means on each key for adjusting said compensatinglevers independently of each other relative to their jacks and saidcompensator-bar to preserve the regulation effected by the first-namedadjusting means.

7. In a piano-action, the combination with a set of hammers, their jacksand jack-levers, and the hammer-rail, of a compensator-bar, acompensating lever pivoted on the lifting-rod of each jack-lever andarranged to be engaged by said bar to shift the jacks when the hammersare moved forward by the hammer-rail, an operating connection betweensaid compensator-bar and the pedal for operating the hammer-rail, and anadjustable post on each key for adjusting said compensating leversindependently of each other relative to their jacks and which postsserve as the fulcrums for said levers during the compensating movement.

This specification signed and witnessed this 15th day of February, 1902.

WILLIAM KRETER.

Witnesses:

WM. PELZER, ANNA PELZER

